My Suburban (117,000 miles, 4 years old) starts fine when cold. When hot (I drive for a couple of hours, turn it off, then try to start it again a few minutes later) It turns over very, very slowly, almost as if the battery was weak. However, if I let it cool a while it will start more easily. In point of fact it has never failed to start even when cranking hot… it just sounds like it’s not gonna start.
Either a starter going bad or an engine going bad. When the symptom occurs, crank the engine by hand with a socket wrench on the crankshaft pulley nut (do this first when the engine is cold, to see how much effort it takes). If it rotates with normal effort, the engine’s OK and the starter’s bad. If it’s very hard to rotate, an engine overhaul is the cure.
I got a Chevy with a 4.3. It was cranking pretty slow until one day it wouldn’t crank at all. I just figured it was the battery and hooked the jumpers up, it still cranked slow but when it started the belt immediately went up in flames, turned out the bearings in the alternater were froze up.
It wouldn’t be the alternator because it starts fine when cold. Never heard of an engine “going bad” like this Gary T. I’ll bet anything it’s the starter.
It’s not as common as starters wearing out, but it does happen.